CN111193318A - Power supply switching device and power supply system - Google Patents
Power supply switching device and power supply system Download PDFInfo
- Publication number
- CN111193318A CN111193318A CN202010096721.2A CN202010096721A CN111193318A CN 111193318 A CN111193318 A CN 111193318A CN 202010096721 A CN202010096721 A CN 202010096721A CN 111193318 A CN111193318 A CN 111193318A
- Authority
- CN
- China
- Prior art keywords
- converter
- power
- power supply
- switch
- controller
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Images
Classifications
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J9/00—Circuit arrangements for emergency or stand-by power supply, e.g. for emergency lighting
- H02J9/04—Circuit arrangements for emergency or stand-by power supply, e.g. for emergency lighting in which the distribution system is disconnected from the normal source and connected to a standby source
- H02J9/06—Circuit arrangements for emergency or stand-by power supply, e.g. for emergency lighting in which the distribution system is disconnected from the normal source and connected to a standby source with automatic change-over, e.g. UPS systems
Abstract
The embodiment of the invention provides a power supply switching device and a power supply system, wherein the device comprises a controller and a converter; the input end of the converter is connected with a first power supply, the output end of the converter is connected with load equipment, and the control end of the converter is connected with the controller; the controller is used for sending a control instruction to the converter when the power supply of the load equipment is switched from the first power supply to the second power supply; and the converter is used for performing power conversion on the alternating current output by the first power supply according to the control instruction, outputting the alternating current after power conversion to the load equipment, and controlling the power of the alternating current after power conversion to be reduced to zero according to a preset change rule. The embodiment of the invention can avoid the generation of circulation current in the power supply circuit when the power supply is switched, thereby avoiding the disturbance or power failure event caused by the circulation current and improving the reliability of power supply.
Description
Technical Field
The embodiment of the invention relates to the technical field of electric power, in particular to a power supply switching device and a power supply system.
Background
With the development of economy, the load side has higher and higher requirements for reliability of power utilization, and at the same time, the tolerance for the power utilization interruption time becomes lower and lower. How to improve the power supply reliability of a power distribution network is a problem which needs to be solved urgently in the power industry. Considering the fluctuation of the load of the power distribution network and the problem of overload of part of power sources caused by the fluctuation, switching the power sources of the power distribution network is a powerful means for improving the reliability of power supply.
In the prior art, two power supplies exist in a power distribution network, wherein one power supply supplies power to load equipment when the power distribution network operates normally, the other power supply is a standby power supply, and the power supply of the load equipment can be switched to the other power supply when the power distribution network is abnormal, so that the normal power supply of the load equipment is ensured.
However, when the power supply of the load equipment is switched from one power supply to another power supply, if the load equipment is connected to the other power supply immediately before the load equipment is disconnected from the one power supply, a circulating current is generated in a power supply line, and if the circulating current is large, the power switch automatically trips, so that the load equipment fails.
Disclosure of Invention
The embodiment of the invention provides a power supply switching device, which aims to solve the problem that power failure caused by circulation current is easily caused when power supply switching is carried out on load equipment at present.
In a first aspect, an embodiment of the present invention provides a power switching apparatus, including: a controller and a converter;
the input end of the converter is connected with a first power supply, the output end of the converter is connected with load equipment, and the control end of the converter is connected with the controller;
the controller is used for sending a control instruction to the converter when the power supply of the load equipment is switched from the first power supply to the second power supply;
and the converter is used for performing power conversion on the alternating current output by the first power supply according to the control instruction, outputting the alternating current after power conversion to the load equipment, and controlling the power of the alternating current after power conversion to be reduced to zero according to a preset change rule.
In a possible embodiment, the apparatus further comprises a first switch and a second switch;
two ends of the first switch are respectively connected with the first power supply and the load equipment, and two ends of the second switch are respectively connected with the second power supply and the load equipment; the controller is respectively connected with the control end of the first switch and the control end of the second switch;
the controller is configured to, when receiving a switching instruction, instruct to switch the power supply of the load device from the first power supply to a second power supply, control the first switch to be turned off, send a control instruction to the converter, and control the second switch to be turned on.
In one possible embodiment, the apparatus further comprises a third switch;
two ends of the third switch are respectively connected with the output end of the converter and the load equipment; the control end of the third switch is connected with the controller;
the controller is further configured to control the third switch to be closed after receiving the switching instruction and before controlling the first switch to be opened, and to control the third switch to be opened when the power of the alternating current output by the converter is reduced to zero.
In a possible embodiment, the number of the third switches is multiple, the load devices are multiple, and the output end of the converter is connected to one load device through each third switch.
In a possible embodiment, the apparatus further comprises a fourth switch;
two ends of the fourth switch are respectively connected with the first power supply and the input end of the converter; the control end of the fourth switch is connected with the controller;
the controller is also used for controlling the on-off of the fourth switch.
In one possible embodiment, the converter comprises an ac-dc converter.
In one possible embodiment, the ac-dc converter comprises an ac-dc converter and a dc-ac converter;
the input end of the AC-DC converter is used as the input end of the converter, the output end of the AC-DC converter is connected with the input end of the DC-AC converter, and the output end of the DC-AC converter is used as the output end of the converter;
the alternating current-direct current converter is a current type converter or a voltage type converter, and the direct current-alternating current converter is a voltage type converter.
In one possible embodiment, the control command is used to instruct the power of the alternating current output by the converter control to gradually decrease to zero within a preset time period.
In a possible embodiment, the controller is specifically configured to:
monitoring a signal parameter of the alternating current output by the converter, determining a regulating quantity according to the signal parameter, and controlling the regulating quantity to the converter so as to reduce the power of the alternating current output by the converter to zero according to a preset change rule.
In a second aspect, an embodiment of the present invention provides a power supply system, including: comprising a first power supply, a load device, and a power switching apparatus as described in the first aspect and various embodiments of the first aspect.
The power supply switching device and the power supply system provided by the embodiment of the invention comprise a controller and a converter; the input end of the converter is connected with a first power supply, the output end of the converter is connected with load equipment, and the control end of the converter is connected with the controller; the controller is used for sending a control instruction to the converter when the power supply of the load equipment is switched from a first power supply to a second power supply; the converter is used for performing power conversion on the alternating current output by the first power supply according to the control instruction and outputting the alternating current after the power conversion to load equipment, and the power of the alternating current after power conversion is controlled to be reduced to zero according to a preset change rule, and by additionally arranging a converter between a first power supply and load equipment, when the power supply of the load equipment is switched from a first power supply to a second power supply, the controller controls the converter to perform frequency conversion on the alternating current output by the first power supply and then supply power to the load equipment, controls the power of the alternating current to be reduced to zero according to a preset change rule, therefore, the power supply of the load equipment by the first power supply can be slowly cut off, the power supply power of the load equipment is gradually borne by the second power supply, the circulation current generated in a power supply circuit during power supply switching is avoided, the power failure event caused by the circulation current is further avoided, and the reliability of power supply is improved.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.
Fig. 1 is a schematic structural diagram of a power switching device according to an embodiment of the invention;
fig. 2 is a schematic structural diagram of a power switching device according to another embodiment of the invention;
fig. 3 is a schematic structural diagram of a power switching device according to another embodiment of the invention;
fig. 4 is a schematic structural diagram of a power switching device according to still another embodiment of the invention;
FIG. 5 is a schematic diagram of a transducer assembly according to an embodiment of the present invention;
FIG. 6 is a schematic diagram of a controller controlling the output power of an exchanger according to an embodiment of the present invention;
fig. 7A to 7D are schematic diagrams of a power switching process according to an embodiment of the invention;
description of reference numerals:
100: a controller;
200: a converter;
300: a first power supply;
400: a load device;
500: a second power supply;
600: a first switch;
700: a second switch;
800: a third switch;
900: and a fourth switch.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
The terms "first," "second," "third," "fourth," and the like in the description and in the claims, as well as in the drawings, if any, are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used is interchangeable under appropriate circumstances such that the embodiments of the invention described herein are capable of operation in sequences other than those illustrated or described herein. Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed, but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.
The technical solution of the present invention will be described in detail below with specific examples. The following several specific embodiments may be combined with each other, and details of the same or similar concepts or processes may not be repeated in some embodiments.
With the development of economy, the load side has higher and higher requirements for reliability of power utilization, and at the same time, the tolerance for the power utilization interruption time becomes lower and lower. How to improve the power supply reliability of a power distribution network is a problem which needs to be solved urgently in the power industry. Considering the fluctuation of the load of the power distribution network and the problem of overload of part of power sources caused by the fluctuation, switching the power sources of the power distribution network is a powerful means for improving the reliability of power supply.
In the prior art, two power supplies exist in a power distribution network, wherein one power supply supplies power to load equipment when the power distribution network operates normally, the other power supply is a standby power supply, and the power supply of the load equipment can be switched to the other power supply when the power distribution network is abnormal, so that the normal power supply of the load equipment is ensured.
However, when the power supply of the load equipment is switched from one power supply to another power supply, if the load equipment is connected to the other power supply immediately before the load equipment is disconnected from the one power supply, a circulating current is generated in a power supply line, and if the circulating current is large, the power switch automatically trips, so that the load equipment fails.
In the embodiment of the present invention, the converter 200 is additionally arranged between the first power supply 300 and the load device 400, when the power supply of the load device 400 is switched from the first power supply 300 to the second power supply 500, the controller 100 controls the converter 200 to perform frequency conversion on the ac output by the first power supply 300 and then supply power to the load device 400, and controls the power of the ac to be reduced to zero according to the preset change rule, so that the power supply of the load device 400 by the first power supply 300 can be slowly disconnected, a circulation current generated in a power supply line during power supply switching is avoided, a disturbance or a power failure event caused by the circulation current is further avoided, and the reliability of power supply is improved.
Fig. 1 is a schematic structural diagram of a power switching device according to an embodiment of the invention. Referring to fig. 1, the present embodiment provides a power switching apparatus including a controller 100 and an inverter 200.
The input terminal of the converter 200 is connected to the first power source 300, the output terminal of the converter 200 is connected to the load device 400, and the control terminal of the converter 200 is connected to the controller 100.
And a controller 100 for transmitting a control command to the inverter 200 when the power supply of the load device 400 is switched from the first power supply 300 to the second power supply 500.
The converter 200 is configured to perform power conversion on the ac power output by the first power supply 300 according to the control instruction, output the ac power after the power conversion to the load device 400, and control the power of the ac power after the power conversion to be reduced to zero according to a preset change rule.
In this embodiment, the first power source 300 may be a power source during normal operation of the power distribution network, and the second power source 500 may be a backup power source of the power distribution network, and is used to replace the first power source 300 to supply power to the load device 400 when the power distribution network is abnormal.
The converter 200 is connected between the first power source 300 and the load device 400, and is configured to convert power of the ac power output by the first power source 300 during power switching, and output the converted ac power to the load device 400 to supply power to the load device 400. The controller 100 is configured to control the power of the ac power output by the converter 200, so that the ac power output by the converter 200 during the power switching process is reduced to zero according to a preset variation law. The converter 200 initially outputs an ac power equal to the power supplied by the first power source 300, and then reduces the output ac power from the power supplied by the first power source 300 to zero according to the control command of the controller 100. The preset change rule may be preset by a user, for example, the preset change rule may be that the initial power supply is reduced to zero within a preset time period, or the initial power supply is reduced to zero according to a preset reduction rate, which is not limited herein. The initial power supply may be the power supply power provided when the load device is supplied with power from the first power source alone.
The controller 100 may determine to switch the power supply of the load device 400 from the first power supply 300 to the second power supply 500 according to an instruction input by a user, or determine to switch the power supply of the load device 400 from the first power supply 300 to the second power supply 500 when the power supply line is abnormal by monitoring the power supply line between the first power supply 300 and the load device 400, which is not limited herein. For example, when the power supply of the load device 400 needs to be switched, the user may input an instruction to the controller 100, and the controller 100 sends a control instruction to the inverter 200, so that the inverter 200 performs power conversion on the ac power output by the first power supply 300, outputs the ac power after the power conversion to the load device 400, and controls the power of the ac power after the power conversion to be reduced to zero according to a preset change rule. Since the power supplied from the first power source 300 to the load device 400 is gradually reduced to zero by the converter 200, the power supplied from the load device 400 by the first power source 300 is gradually switched to the power supplied by the second power source 500, thereby preventing the circulation current from being generated in the power supply line of the load device 400.
The power switching device provided by the embodiment of the invention comprises a controller 100 and a converter 200; the input end of the converter 200 is connected with the first power supply 300, the output end of the converter 200 is connected with the load device 400, and the control end of the converter 200 is connected with the controller 100; a controller 100 for transmitting a control command to the inverter 200 when the power supply of the load device 400 is switched from the first power supply 300 to the second power supply 500; the converter 200 is used for performing power conversion on alternating current output by the first power supply 300 according to a control instruction, outputting the alternating current after the power conversion to the load equipment 400, and controlling the power of the alternating current after the power conversion to be reduced to zero according to a preset change rule, by additionally arranging the converter 200 between the first power supply 300 and the load equipment 400, when the power supply of the load equipment 400 is switched from the first power supply 300 to the second power supply 500, the controller 100 controls the converter 200 to perform frequency conversion on the alternating current output by the first power supply 300 and then supply power to the load equipment 400, and controls the power of the alternating current to be reduced to zero according to the preset change rule, so that the power supply of the load equipment 400 from the first power supply 300 can be slowly cut off, the power supply power of the load equipment 400 is gradually borne by the second power supply 500, the generation of a circular current in a power supply line during the power supply switching is avoided, and further the occurrence of disturbance or, the reliability of power supply is improved.
Alternatively, the controller 100 may control the inverter 200 to be in an on-state or an off-state. When power switching for the load device 400 is not required, the controller 100 may control the converter 200 to turn off the operation state, in which the first power supply 300 directly supplies power to the load device 400 through the other connection line. When power switching needs to be performed on the load device 400, the controller 100 may control the converter 200 to start an operating state, perform power conversion on the ac output by the first power source 300 through the converter 200, output the ac to the load device 400, supply power to the load device 400, and disconnect other connection lines between the first power source 300 and the load device 400, and at the same time, the controller 100 may control the second power source 500 to start supplying power to the load device 400. After the power of the ac power output from the converter 200 is gradually reduced to zero, the entire power of the load device 400 is supplied by the second power source 500, and the controller 100 may turn off the converter 200. In this embodiment, the converter 200 is turned on only during power switching, and is otherwise off. During the period when the converter 200 gradually reduces the output ac power to zero, the power supply of the load device 400 is gradually supplied by the first power supply 300, is supplied by both the first power supply 300 and the second power supply 500, and is finally supplied by the second power supply 500, so that the switching of the power supply is realized.
Fig. 2 is a schematic structural diagram of a power switching device according to another embodiment of the present invention. Referring to fig. 2, in one possible embodiment, the apparatus further comprises a first switch 600 and a second switch 700.
The first switch 600 has two terminals connected to the first power supply 300 and the load device 400, respectively, and the second switch 700 has two terminals connected to the second power supply 500 and the load device 400, respectively. The controller 100 is connected to a control terminal of the first switch 600 and a control terminal of the second switch 700, respectively.
The controller 100 is configured to, upon receiving a switching instruction, instruct switching of the power supply of the load device 400 from the first power supply 300 to the second power supply 500, control the first switch 600 to be turned off, send a control instruction to the converter 200, and control the second switch 700 to be turned on.
In the present embodiment, the first switch 600 is connected in parallel with the inverter 200 between the first power source 300 and the load device 400. When the first switch 600 is closed, the first power supply 300 supplies power to the load device 400 through the line on which the first switch 600 is located. The second switch 700 is connected between the second power supply 500 and the load device 400. When the second switch 700 is closed, the second power supply 500 supplies power to the load device 400 through the line on which the second switch 700 is located. The power source for supplying power to the load device 400 can be selected by the controller 100 controlling the first switch 600 and the second switch 700.
Before the power switching is performed, the first switch 600 is closed, and the load device 400 is supplied with power from the first power supply 300. After the controller 100 receives a switching instruction input by a user, the controller 100 first controls the converter 200 to start a working state, so that the converter 200 performs power conversion on the alternating current output by the first power supply 300 and outputs the alternating current to the load device 400 to supply power to the load device 400, controls the first switch 600 to be switched off, stops the first power supply 300 from directly supplying power to the load device 400, and controls the second switch 700 to be switched on to start the second power supply 500 to supply power to the load device 400; then, the alternating current electric power output by the converter 200 is controlled to be gradually reduced to zero by the power supply power of the first power supply 300; and finally, controlling the converter 200 to be in a working state, so as to realize the switching of the power supply of the load equipment 400.
Fig. 3 is a schematic structural diagram of a power switching device according to another embodiment of the invention. Referring to fig. 3, in one possible embodiment, the apparatus further includes a third switch 800.
Both ends of the third switch 800 are connected to the output terminal of the converter 200 and the load device 400, respectively. A control terminal of the third switch 800 is connected to the controller 100.
The controller 100 is further configured to control the third switch 800 to close after receiving the switching instruction and before controlling the first switch 600 to open, and control the third switch 800 to open when the power of the ac power output by the inverter 200 decreases to zero.
In this embodiment, the third switch 800 is connected between the inverter 200 and the load device 400, and the inverter 200 can transmit the output ac power to the load device 400 only when the third switch 800 is closed. The controller 100 can control the on/off of the line on which the converter 200 is located by controlling the third switch 800, thereby performing more accurate power switching control.
Before the power switching is performed, the first switch 600 is closed, and the load device 400 is supplied with power from the first power supply 300. After the controller 100 receives a switching instruction input by a user, the controller 100 first controls the third switch 800 to be closed, so that the converter 200 performs power conversion on the alternating current output by the first power supply 300 and outputs the alternating current to the load device 400 to supply power to the load device 400, controls the first switch 600 to be opened, stops the first power supply 300 from directly supplying power to the load device 400, and controls the second switch 700 to be closed, so that the second power supply 500 starts to supply power to the load device 400; then, the alternating current electric power output by the converter 200 is controlled to be gradually reduced to zero by the power supply power of the first power supply 300; and finally, the third switch 800 is controlled to be switched off, so that the power supply of the load device 400 is switched.
Optionally, the number of the third switches 800 is multiple, the load devices 400 are multiple, and the output end of the converter 200 is connected to one load device 400 through each third switch 800.
In this embodiment, one converter 200 can perform power switching for the multiple load devices 400. The output of the converter 200 is connected to the respective load devices 400 via each third switch 800. The controller 100 may control each third switch 800 in sequence according to the control manner in the embodiment of fig. 3 to perform power switching on each load device 400.
Fig. 4 is a schematic structural diagram of a power switching device according to still another embodiment of the invention. Referring to fig. 4, in one possible embodiment, the apparatus further comprises a fourth switch 900.
Both ends of the fourth switch 900 are connected to the first power supply 300 and the input terminal of the inverter 200, respectively. A control terminal of the fourth switch 900 is connected to the controller 100.
The controller 100 is further configured to control on/off of the fourth switch 900.
In this embodiment, the fourth switch 900 is connected between the first power supply 300 and the inverter 200. When the converter 200 needs to be repaired or replaced, the controller 100 can control the third switch 800 and the fourth switch 900 to be disconnected, so that the converter 200 is separated from the power distribution network, and an operator can safely repair or replace the converter 200.
Optionally, the converter 200 comprises an ac-dc converter.
In this embodiment, the converter 200 may be an ac-dc-ac converter. The ac-dc converter converts the ac power output from the first power source 300 into dc power, converts the dc power into ac power, and outputs the ac power to the load device 400. The controller 100 may control the power of the alternating current output by the inverter 200 by controlling a conversion process of converting direct current into alternating current.
Optionally, the ac-dc converter comprises an ac-dc converter and a dc-ac converter.
The input end of the ac-dc converter is used as the input end of the converter 200, the output end of the ac-dc converter is connected with the input end of the dc-ac converter, and the output end of the dc-ac converter is used as the output end of the converter 200.
In this embodiment, the input terminal of the ac/dc converter is connected to the first power supply 300 as the input terminal of the converter 200. The output of the dc-ac converter is connected to the load device 400 as the output of the converter 200. The ac-dc converter is configured to convert ac power output from the first power supply 300 into dc power, and the dc-ac converter is configured to convert the dc power into ac power and output the ac power to the load device 400. The controller 100 may be coupled to the dc-to-ac converter to control the supply frequency of the output by controlling the dc-to-ac converter.
Optionally, the ac-dc converter is a current-type converter or a voltage-type converter, and the dc-ac converter is a voltage-type converter.
In this embodiment, as shown in fig. 5, the converter 200 may have two implementation forms, a combination 1 and a combination 2, and in the combination 1, the converter 200 is formed by combining a current-type ac/dc converter and a voltage-type dc/ac converter. In combination 2, the inverter 200 is a combination of a voltage-type ac/dc converter and a voltage-type dc/ac converter.
Wherein the current-type converter may include, but is not limited to, at least one of: diode converter, power supply commutation converter, from commutation converter. The voltage source converter may include, but is not limited to, at least one of: two-level converters, three-level converters, multi-level converters, modular multi-level converters.
Optionally, the control instruction is used to instruct the converter 200 to gradually decrease the power of the alternating current output by the control to zero within a preset time period.
In this embodiment, the preset time period may be set by a user, for example, the preset time period may be 10 milliseconds, 50 milliseconds, and the like, but is not limited thereto, and the controller 100 may control the power of the alternating current output by the converter 200 to gradually decrease to zero within the preset time period through the control instruction. By adjusting the preset duration, the user can control the reduction speed of the power supply power when the converter 200 supplies power to the load device 400, so that no backflow is generated in the power supply line in the power supply switching process and the operation of the load device 400 is not affected.
Optionally, the controller 100 is specifically configured to:
monitoring a signal parameter of the alternating current output by the converter 200, determining a regulating quantity according to the signal parameter, and controlling the regulating quantity to the converter 200 so as to reduce the power of the alternating current output by the converter 200 to zero according to a preset change rule.
In this embodiment, the signal parameter may include a real component and a reactive component, wherein the real component includes, but is not limited to, at least one of the following: active power, alternating voltage frequency, direct voltage. Reactive components include, but are not limited to, reactive power and ac voltage magnitude. The converter 200 may include an ac-dc converter and a dc-ac converter. The controller 100 may monitor a signal parameter of the ac power output by the dc-to-ac converter, determine a manipulated variable based on the signal parameter, and control the dc-to-ac converter with the manipulated variable to gradually reduce the power of the ac power output by the dc-to-ac converter to zero.
For example, the controller 100 can decouple the active and reactive currents of the ac output by the converter 200, so as to independently control the active and reactive components, thereby achieving smooth control of the power of the converter 200. As shown in fig. 6, the control link of the controller 100 for the dc-ac converter is mainly divided into two links, i.e., an inner loop and an outer loop, where the inner loop is a current control loop and the outer loop is a power component control loop. The controller 100 may include an outer loop controller and an inner loop controller. The outer-loop controller obtains an active component and a reactive component by measuring the output current and voltage of the converter 200, wherein the active component mainly comprises active power, alternating voltage frequency, direct current voltage and the like, and the reactive component mainly comprises reactive power and alternating voltage amplitude. The active power component passes through the controller 100 to obtain a corresponding active current command Id, and the reactive power component passes through the controller 100 to obtain a corresponding reactive current command Iq. The inner Loop controller mainly includes a PLL (Phase Locked Loop), a dq-abc coordinate converter, and a current controller 100. The phase position omega, dq-abc coordinate converter of which the output signal of the PLL is an alternating voltage is used for converting three-phase currents Ia, Ib and Ic measured in a static coordinate system into active current Id measurement and reactive current Iq measurement in a rotating coordinate system, and simultaneously can also be used for converting a command of outputting active voltage Ud and reactive voltage Uq by a current controller in the rotating coordinate system back to three-phase voltages Ua, Ub and Uc in the static coordinate system to serve as output voltage reference values of the converter 200. In this example, the controller 100 first controls the frequency and amplitude of the output ac voltage during the power switching process, i.e., the two quantities are used as the control targets of the active component and the reactive component, and the power supply of the load device 400 is maintained by controlling the two quantities. After the second switch 700 is closed, the control object of the controller 100 may be switched to active power and reactive power, so as to ensure that the original output power to the load device 400 is unchanged, so as to realize that all the load power is provided by the power supply on the local side, and then gradually reduce the output power to zero, in this process, the controller 100 responds accordingly, thereby ensuring that the output power is gradually reduced to zero.
The following describes a power switching process of the power switching device by using an embodiment, but the invention is not limited thereto. Referring to fig. 7A to 7D, the power supply provided by the substation 1 represents a first power supply 300, the power supply provided by the substation 2 represents a second power supply 500, the load 1 represents a first load device 400, and the load 2 represents a second load device 400. Taking the power supply switching of the load 1 as an example, the specific steps are as follows:
in step one, the controller 100 controls the third switch 800 and the fourth switch 900 to be closed, as shown in fig. 7A.
Step two, the controller 100 controls the first switch 600 to be turned off, and the load 1 is powered by the ac power output by the inverter 200, as shown in fig. 7B.
Step three, the controller 100 controls the second switch 700 to close and controls the ac power output by the converter 200 to gradually decrease to zero, as shown in fig. 7C.
Step four, after the ac power output by the converter 200 is reduced to zero, the controller 100 controls the third switch 800 to be turned off, and at this time, the load 1 is switched from the first power source 300 to the second power source 500, as shown in fig. 7D.
After the power switching of the load 1 is completed, the above steps may be performed to perform the power switching of the load 2, which is not described herein again.
The embodiment of the invention also provides a power supply system. The power supply system includes the first power supply 300, the load device 400, and the power supply switching device as described above. Optionally, the load device 400 is connected to the first power supply 300 through a first switch 600, and when the first switch 600 is closed, the first power supply 300 supplies power to the load device 400. The power supply system may further include a second power supply 500. The load device 400 is connected to the second power supply 500 through the second switch 700, and when the second switch 700 is closed, the second power supply 500 supplies power to the load device 400. The implementation principle of the power supply system can be referred to the implementation principle of the power switching device, and is not described herein again.
The power supply system provided by the embodiment of the invention comprises a first power supply 300, a load device 400 and a power supply switching device, wherein the power supply switching device comprises a controller 100 and a converter 200; the input end of the converter 200 is connected with the first power supply 300, the output end of the converter 200 is connected with the load device 400, and the control end of the converter 200 is connected with the controller 100; a controller 100 for transmitting a control command to the inverter 200 when the power supply of the load device 400 is switched from the first power supply 300 to the second power supply 500; the converter 200 is used for performing power conversion on alternating current output by the first power supply 300 according to a control instruction, outputting the alternating current after power conversion to the load equipment 400, and controlling the power of the alternating current after power conversion to gradually reduce to zero, by additionally arranging the converter 200 between the first power supply 300 and the load equipment 400, when the power supply of the load equipment 400 is switched from the first power supply 300 to the second power supply 500, the controller 100 controls the converter 200 to perform frequency conversion on the alternating current output by the first power supply 300 and then supply power to the load equipment 400, and controls the power of the alternating current to gradually reduce to zero, so that the power supply of the load equipment 400 from the first power supply 300 can be slowly cut off, the power supply of the load equipment 400 is gradually borne by the second power supply 500, the circulation current generated in a power supply line during power supply switching is avoided, and further the disturbance or power failure event caused by the circulation current is avoided, the reliability of power supply is improved.
Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.
Claims (10)
1. A power switching apparatus, comprising: a controller and a converter;
the input end of the converter is connected with a first power supply, the output end of the converter is connected with load equipment, and the control end of the converter is connected with the controller;
the controller is used for sending a control instruction to the converter when the power supply of the load equipment is switched from the first power supply to the second power supply;
and the converter is used for performing power conversion on the alternating current output by the first power supply according to the control instruction, outputting the alternating current after power conversion to the load equipment, and controlling the power of the alternating current after power conversion to be reduced to zero according to a preset change rule.
2. The power switching device of claim 1, further comprising a first switch and a second switch;
two ends of the first switch are respectively connected with the first power supply and the load equipment, and two ends of the second switch are respectively connected with the second power supply and the load equipment; the controller is respectively connected with the control end of the first switch and the control end of the second switch;
the controller is configured to, when receiving a switching instruction, instruct to switch the power supply of the load device from the first power supply to a second power supply, control the first switch to be turned off, send a control instruction to the converter, and control the second switch to be turned on.
3. The power switching device of claim 2, further comprising a third switch;
two ends of the third switch are respectively connected with the output end of the converter and the load equipment; the control end of the third switch is connected with the controller;
the controller is further configured to control the third switch to be closed after receiving the switching instruction and before controlling the first switch to be opened, and to control the third switch to be opened when the power of the alternating current output by the converter is reduced to zero.
4. The power switching apparatus according to claim 3, wherein the number of the third switches is plural, the load devices are plural, and the output terminal of the converter is connected to one load device through each of the third switches.
5. The power switching device of claim 3, further comprising a fourth switch;
two ends of the fourth switch are respectively connected with the first power supply and the input end of the converter; the control end of the fourth switch is connected with the controller;
the controller is also used for controlling the on-off of the fourth switch.
6. The power switching apparatus of claim 1, wherein the converter comprises an ac-dc converter.
7. The power switching apparatus according to claim 6, wherein the ac-dc converter includes an ac-dc converter and a dc-ac converter;
the input end of the AC-DC converter is used as the input end of the converter, the output end of the AC-DC converter is connected with the input end of the DC-AC converter, and the output end of the DC-AC converter is used as the output end of the converter;
the alternating current-direct current converter is a current type converter or a voltage type converter, and the direct current-alternating current converter is a voltage type converter.
8. The power switching device of any one of claims 1 to 7, wherein the control command is configured to instruct the converter to gradually decrease the power of the alternating current output by the converter control to zero within a preset time period.
9. The power switching device according to any one of claims 1 to 7, wherein the controller is specifically configured to:
and monitoring a signal parameter of the alternating current output by the converter, determining a regulating quantity according to the signal parameter, and controlling the regulating quantity to the converter so as to reduce the power of the alternating current output by the converter to zero according to the preset change rule.
10. A power supply system comprising a first power source, a load device, and a power switching apparatus as claimed in any one of claims 1 to 9.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010096721.2A CN111193318A (en) | 2020-02-17 | 2020-02-17 | Power supply switching device and power supply system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010096721.2A CN111193318A (en) | 2020-02-17 | 2020-02-17 | Power supply switching device and power supply system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN111193318A true CN111193318A (en) | 2020-05-22 |
Family
ID=70710438
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010096721.2A Pending CN111193318A (en) | 2020-02-17 | 2020-02-17 | Power supply switching device and power supply system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN111193318A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112820565A (en) * | 2020-12-29 | 2021-05-18 | 常熟开关制造有限公司(原常熟开关厂） | Automatic transfer switching device control method and automatic transfer switching device |
Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1918769A (en) * | 2004-02-10 | 2007-02-21 | 利伯特公司 | Scr-based static transfer switch device and method |
| CN102104272A (en) * | 2009-12-17 | 2011-06-22 | 深圳先进技术研究院 | Power supply switching device |
| CN104410088A (en) * | 2014-11-28 | 2015-03-11 | 国家电网公司 | Smooth switching circuit |
| CN104485730A (en) * | 2014-11-28 | 2015-04-01 | 国家电网公司 | Circuit capable of smoothly switching power supply |
| CN106026358A (en) * | 2016-06-23 | 2016-10-12 | 京东方科技集团股份有限公司 | Automatic power supply switching apparatus and method, and power supply system |
| CN106130167A (en) * | 2016-07-11 | 2016-11-16 | 合肥联信电源有限公司 | A kind of out of phase dual power supply apparatus for fast switching |
| US20170133922A1 (en) * | 2015-11-06 | 2017-05-11 | Wisconsin Alumni Research Foundation | Converter control using reduced link capacitor |
| US20190319530A1 (en) * | 2018-04-17 | 2019-10-17 | Abb Schweiz Ag | Method and control system for zero-sequence current compensation for ground current reduction |
-
2020
- 2020-02-17 CN CN202010096721.2A patent/CN111193318A/en active Pending
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1918769A (en) * | 2004-02-10 | 2007-02-21 | 利伯特公司 | Scr-based static transfer switch device and method |
| CN102104272A (en) * | 2009-12-17 | 2011-06-22 | 深圳先进技术研究院 | Power supply switching device |
| CN104410088A (en) * | 2014-11-28 | 2015-03-11 | 国家电网公司 | Smooth switching circuit |
| CN104485730A (en) * | 2014-11-28 | 2015-04-01 | 国家电网公司 | Circuit capable of smoothly switching power supply |
| US20170133922A1 (en) * | 2015-11-06 | 2017-05-11 | Wisconsin Alumni Research Foundation | Converter control using reduced link capacitor |
| CN106026358A (en) * | 2016-06-23 | 2016-10-12 | 京东方科技集团股份有限公司 | Automatic power supply switching apparatus and method, and power supply system |
| CN106130167A (en) * | 2016-07-11 | 2016-11-16 | 合肥联信电源有限公司 | A kind of out of phase dual power supply apparatus for fast switching |
| US20190319530A1 (en) * | 2018-04-17 | 2019-10-17 | Abb Schweiz Ag | Method and control system for zero-sequence current compensation for ground current reduction |
Non-Patent Citations (4)
| Title |
|---|
| S.H. WEINBERG等: "A New High-Efficiency Zero-Voltage, Zero-Current Switching Topology", 《2006 IEEE INTERNATIONAL VACUUM ELECTRONICS CONFERENCE HELD JOINTLY WITH 2006 IEEE INTERNATIONAL VACUUM ELECTRON SOURCES》 * |
| 张淼等: "基于电力电子变流器的电源平滑切换装置", 《电子应用技术》 * |
| 李一龙等: "《智能微电网控制技术》", 31 August 2017 * |
| 潘永雄等: "《开关电源技术与设计 第2版》", 31 March 2019 * |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112820565A (en) * | 2020-12-29 | 2021-05-18 | 常熟开关制造有限公司(原常熟开关厂） | Automatic transfer switching device control method and automatic transfer switching device |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US6465910B2 (en) | System for providing assured power to a critical load | |
| US10284006B2 (en) | Uninterruptible power supply system | |
| KR100997559B1 (en) | System for providing assured power to a critical load | |
| US7372177B2 (en) | Control system, method and product for uninterruptible power supply | |
| EP3116096B1 (en) | Ups circuit | |
| WO2014017417A1 (en) | Distributed power system and operation method | |
| US9444286B2 (en) | Uninterruptible power supply system | |
| CN104272573A (en) | A modular three-phase online UPS | |
| CN113629757A (en) | Energy storage device, energy storage device control method and photovoltaic system | |
| CN107852023A (en) | Uninterrupted power supply(ups) | |
| JP2017519478A (en) | Power bus circuit | |
| CN112467839A (en) | Battery cluster management device and battery energy storage system | |
| CN115776130B (en) | Off-grid switching method, energy storage converter, energy storage system and power system | |
| US11165253B2 (en) | Power control system and control device | |
| EP3806264B1 (en) | Control device and power control system | |
| CN111193318A (en) | Power supply switching device and power supply system | |
| CN116865346B (en) | Energy storage inverter grid-connected and off-grid switching method, system, electronic equipment and storage medium | |
| US10491036B1 (en) | Solid-state automatic transfer switch | |
| CN111262330B (en) | Three-phase UPS bus balancer | |
| JPH1127877A (en) | Uninterruptible power unit | |
| JP2016214030A (en) | Power conversion device | |
| EP2571120B1 (en) | Connection device for electric power converters | |
| CN112703656A (en) | Power supply device and power supply system | |
| CN112703657A (en) | Power supply device and power supply system | |
| CN218888202U (en) | Uninterruptible power supply device and system |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| AD01 | Patent right deemed abandoned | ||
| AD01 | Patent right deemed abandoned |
Effective date of abandoning: 20220701 |